I have a scenario where:

A calls B (i.e.: +19995551212) and puts it on hold.

A calls C (i.e.: +99911111) and when it answers:

The client sends a refer to B to connect to a conference, and then transfers C to the conference.

All this works well, but i need to block specific called numbers from entering the conference.

I can identify the channels as they come in and i'm trying to hangup the leg i want.

I tried with 

<action application="hangup"/>

and also with 

<action application="set" data="res=${uuid_kill(${uuid})}"/>

but all channels are disconnected.

Not sure if i'm doing something wrong.

Any help would be appreciated